错误描述
在jsp页面引入了自定义的TLD文件的时候，碰到了一个错误
Invalid tld file: "/WEB-INF/tags/xxxt.tld", see JSP 2.2 specification section 7.3.1 for more details
错误原因
不符合 JSP2.2 中对tags的规定。
规定说的是这个：
In the jsp-2_2JSP.7.3.1 Identifying Tag Library Descriptors Tag library descriptor files have names that use the extension .tld, and the extension indicates a tag library descriptor file. When deployed inside a JAR file, the tag library descriptor files must be in the META-INF directory, or a subdirectory of it. When deployed directly into a web application, the tag library descriptor files must always be in the WEB-INF directory, or some subdirectory of it. TLD files should not be placed in /WEB-INF/classes or /WEB-INF/lib, and must not be placed inside /WEB-INF/tags or a subdirectory of it, unless named implicit.tld and intended to configure an implicit tag library with its JSP version and tlib-version.the .tld file can't be in classes , lib ,tags folder or subfolder.意思是说，如果你使用的是jsp2.2就不能把tld文件放在 /WEB-INF/tags 以及其子目录下。
jsp版本和tomcat的版本是相关的。jsp版本和tomcat的版本对应关系如下：
| Servlet Spec | JSP Spec | EL Spec | WebSocket Spec | JASPIC Spec | Apache Tomcat Version | Latest Released Version | Supported Java Versions |
|---|---|---|---|---|---|---|---|
| 4.0 | 2.3 | 3.0 | 1.1 | 1.1 | 9.0.x | 9.0.1 (beta) | 8 and later |
| 3.1 | 2.3 | 3.0 | 1.1 | 1.1 | 8.5.x | 8.5.23 | 7 and later |
| 3.1 | 2.3 | 3.0 | 1.1 | N/A | 8.0.x (superseded) | 8.0.47 (superseded) | 7 and later |
| 3.0 | 2.2 | 2.2 | 1.1 | N/A | 7.0.x | 7.0.82 | 6 and later(7 and later for WebSocket) |
| 2.5 | 2.1 | 2.1 | N/A | N/A | 6.0.x (archived) | 6.0.53 (archived) | 5 and later |
| 2.4 | 2.0 | N/A | N/A | N/A | 5.5.x (archived) | 5.5.36 (archived) | 1.4 and later |
| 2.3 | 1.2 | N/A | N/A | N/A | 4.1.x (archived) | 4.1.40 (archived) | 1.3 and later |
| 2.2 | 1.1 | N/A | N/A | N/A | 3.3.x (archived) | 3.3.2 (archived) | 1.1 and later |
详情可查看：http://tomcat.apache.org/whichversion.html
解决办法
1.如果你的tld文件放在 /WEB-INF/tags目录下，而你不想改代码，那么，把tomcat换成apache-tomcat-7.0.55 或者以下的版本。（亲测可行）
2.如果你不想换tomcat就把 tld放在 /WEB-INF下。
Invalid tld file: "/WEB-INF/tags/xxxt.tld", see JSP 2.2 specification section 7.3.1 for more details
原文地址：http://www.cnblogs.com/demingblog/p/7919841.html